Process of removing oil from textile fibers while binding them together by resins



Oct. 13, 1964 T. D. COLE PROCESS OF REMOVING OIL FROM TEXTILE FIBERS WHILE BINDING THEM TOGETHER BY RESINS Filed Dec. 12, 1960 INVENTOF.

AT T PNEY'S United States Patent if, Wllilllllll ll-ll lillNG THEM TUGETl-llllltt BY l. ilfilihlil Thor-as (Iole, Loclrport, N.Y., assignor, by mesne gnrnents, to Lochport Mills Research and Development @orporatlon, a corporation of New Yorlr llllec. 12, 19nd, Ser. No. 75,223 29 Claims. Cl. 264-87) This invention relates to processes for removing oil from fibers various types of vegetable or animal origin and from synthetic fibers while binding them together by resins.

In cotton mills and mills operating on other fibers a certain anount of the fibrous material becomes contaminated with oil or lubricants during the spinning, weaving or other processing of the same, and fibers thus contaminated are generally discarded because they cannot be properly bleached, cleaned, dyed or flame-proofed. This cotton is commonly referred to as cotton mill sweeps or oily card." Such mineral hydrocarbons that commonly contaminate fibers during the various operations on the same are the usual spindle oils, lubricating oils and oils picked up by the fibers through processing or use and are mostly unsaponifiable and ditficult to remove by any washing operations. Mineral oils have heretofore been removed from fibers contaminated with the same by moistening the fibers with water and then subjecting the same to air currents of various temperatures low enough to avoid damage to the cotton but high enough to evaporate the water and carry ofi some of the oils.

it is an object of this invention to provide a fast and clficient process for removing mineral oils from cotton and other fibers while binding them together with resins.

Another object is to provide a process and apparatus of this kind in which the cotton fibers may be caused to adhere to each other to form a non-woven pad or feltlike packing or padding material in sheet form.

Another object of this invention is to utilize an improved construction for collecting and disposing of oil removed from the fibers.

The accompanying drawing shows diagrammatically by way of example, an apparatus by means of which my improved process may be carried out.

The cotton or other fibers to be treated may be introduced into my apparatus in any suitable or desired manner. These fibers are generally received in bales and the compacted mass of fibers may be broken up in any suitable or usual manner before they are introduced to my improved apparatus. Since this treating of the fibers to loosen the same is common practice, it is not deemed necessary to illustrate the same. lowever, the fibers before reaching my improved apparatus are passed through carding or similar machines for combining and cleaning tie fibers, which are also subjected to air currents which loosen them so that they can be readily worked upon. My improved apparatus may be used for merely removing mineral oils from the fibers without causing the fibers to adhere to each other, but if it is desired to form the fibers into a non-woven pad or felt-like sheet, a resinous or plastic substance in finely divided or liquid form is mixed with the cotton fibers during the treating of the same with an air blast by introducing the finely divided or liquid plastic substance into the air blast. The amount of this substance may vary from 8% to 40% of the weight of the fibers, depending on the degree of flexibility or stiffness desired in the final product.

The material in the form of loose fibers is then fed from any suitable guide means or conveyor indicated diagrammatically at between two rolls 6 to a belt conveyor 7 which feeds the mass of material into the housing 2 8 of my improved apparatus through an inlet opening 9 therein. Any other means for introducing the fibrous material into the apparatus may be employed.

Within the housing of the apparatus I provide a pair of conveyor belts lid and ll. arranged one above the other, to run together at an approximately equal speed so as not to roll the material up in rolls. These belts may be of any suitable or desired readily pervious structure through which air can pass, and the mass or layer of loose fibrous material 12 is fed between the two conveyor belts which pass around pulleys or rolls l4- and 15 so that the material entering the apparatus will be supported by the upper run of the lower conveyor lit and will be held in correct relation to the lower conveyor by means of the upper run of the upper conveyor. These conveyors also hold the fibers against being blown away by air blasts to which the material is subjected. It may, of course, be desired to produce material of this kind in sheets of different thicknesses and for this reason either or both of the rolls 1d and 15 over which the conveyors pass are adjustable relatively to each other by any suitable or well known means, not shown. The material on entering between the two conveyors is compressed approximately to the desired thickness and is maintained in this condition by the con veyors. After passing through the apparatus, the material passes through a discharge slot or opening 16 of the housing of the apparatus and is then deposited upon a conveyor 17 by means of which it is removed from the apparatus.

While the material l2 passes through the apparatus it is subjected to heated air currents which pass through the mass of material. For this purpose the interior of the housing 8 is provided with partitions or walls 2i: and it which are provided with openings or passages through which the conveyors and the material deposited thereon may pass from the left in the drawing to the right. The air, after each passage through the material, is changed so that it will not become too heavily laden with vapor of the oils which have been removed from the material and thus prevent the air from becoming combustible or explosive. The air is also heated to relatively high temperatures which would eventually char or damage the fibers, but the conveyors 10 and 11 are run at a sufficiently high speed so that the fibers are not adversely affected by the heat even though the temperature of the air which passes through the mass of material is sufiiciently high so that it would char or damage the fibers if they were exposed thereto for a suificient length of time.

Air may be heated for passage through the apparatus in any suitable or desired manner. For example, in the construction shown in the drawings, a furnace or heater 25 is provided which has an inlet 26 at one end thereof through which a burner nozzle 27 projects and the furnace is also provided with a discharge opening 28. The nozzle 27 is spaced at considerable distance from the edges of the inlet opening its so that a considerable amount of air is drawn into the furnace to support combustion and also to mix with the products of combustion for passage to the housing 8. The term air is herein employed to designate also a mixture of products of combustion and oil vapors with air.

The discharge opening 28 discharges the products of combustion and air into a conduit 3b which is open at one end 311 to receive fresh air. This conduit also recessives heated air and products of combustion from the furnace 25 through the discharge opening 28. The air o) in the housing as indicated by the arrows. This air consequently passes through the portion of the material 12 after this material has passed through the other two stations, and after a considerable amount of oil has been removed therefrom. Since this air is relatively free from oil vapor, it consequently readily vaporizes and removes all or most of the oil remaining in the material prior to the discharge of the same through the opening 16.

This air then passes below the partition 21 into the middle compartment of the housing 8 and may be sup plemented by fresh air and products of combustion passing through a branch conduit 36 of the conduit 34. This air which has passed through a portion of the material 12 together with fresh air from the branch conduit 36 then passes upwardly through the material 12 on the conveyor in the middle portion of the housing between the partitions 20 and 21. After passing through the material in the middle portion of the housing between the conveyors, this air and gas pass over the upper end of the partition 20 and are then directed downwardly for passage through the material 12 which has just entered the apparatus. Some fresh air and gases from the conduit 34 may join the air and gases which have just passed through the material betweeri'fthe partitions 2t) and 21. For this purpose a branch passage 33 is provided which connects with the upper end of conduit 34. Both branch passages 36 and 38 are controlled by suitable valves 39 and 40 so that the quantity of air passing through these branch passages may be controlled to suit the particular material which is being treated.

The air and gas after having passed through the layer of material just entering the apparatus is then passed to a conduit 42, but if desired, a part of this mixture of air and gas may pass through a branch conduit 43 controlled by a valve 44. The branch conduit 43 connects with the fresh air inlet conduit 30 so that some of the heated air and gases may mix with the incoming cold air and thus reduce to a certain extent the amount of fuel required to raise the air and gas to the desired temperature.

The conduit 42 conducts the air from the apparatus to a fan or blower 46 which draws the air from. the apparatus and discharges it through a discharge stack 47 to the atmosphere.

In the operation of my process in this part of the apparatus the air and gas passing through the conduit 34 to the material of the conveyor which is about to leave the apparatus may be elevated ordinarily to temperatures ranging between 325 to 375 degrees F. although these temperatures may be varied considerably. For example, if the conveyors are operated at a sufiicient speed, the temperature of the air and gases in the conduit 41 may be raised to as much as 430 degrees F., this temperature being desirable if a vinyl resin is mixed with the fibers. If a phenolic resin is employed the apparatus may operate at a temperature of about 350 degrees F. In either case the melting of the resin absorbs much of the heat of the air, so that the fibers are protected against damage by overheating.

The speed of travel of the fibrous material through the apparatus may vary from 7 to 40 feet per minute. If, for example, the apparatus is thirty feet long, material may be passed through the apparatus in approximately from one to four minutes depending upon the temperature of the incoming air and gas and upon other conditions such as the density or thickness of the material. If a higher temperature is employed, the material should be passed through the apparatus in about one minute or less to avoid damage to the material.

If the material treated in the apparatus has not been mixed with any plastic or resinous substances, the material 12 will contain a minimum of mineral oil and may be used for many purposes for which fibers may be employed. If, however plastic or resinous substances have been mixed with the fibers before they have been fed to the apparatus, the high temperature will cause these substances to become melted and to adhere to the fibers so that many of fibers will adhere toadjacent fibers and thus form a sheet of non-woven material which is similar to felt and which may be used for packing, padding and many other purposes. In a material of this type the fibers adhere to each other sumciently so that the sheet of material discharged from the apparatus can be readily flexed, bent and otherwise handled as a sheet rather than as a mass of loose disconnected fibers. It is of course possible to introduce an excess of resin or plastic substances so that the resulting fibrous material discharged from the apparatus will be relatively stifl? and hard. The apparatus is very versatile and can be used for making sheet materials of radically ditferent properties and also of different thickness, this variation in thickness being effected by adjusting the conveyors relatively to each other.

By passing a sheet of material between the conveyors the material is initially compressed to the desired extent and is maintained at approximately this compression during its passage through the apparatus, thus controlling the thickness of the resulting sheet. The space between the conveyors may also be used for controlling the softness or degree of compacting of the resulting material since it is obvious that material if treated to very little compression between the conveyors will be quite light per unit of volume and will be readily flexible. 0n the other hand, by moving the conveyor belts toward each other the fibrous material may be more compacted, thus producing a firmer and less flexible product. The thickness of the resulting material may also be varied by controlling the quantity of material supplied to the apparatus. It will of course be obvious that the pressure of the air supplied to the apparatus must be varied depending upon the thickness of the layer of material passing through the apparatus.

The air and gas mixture discharged from the apparatus contains a considerable quantity of vapor of the oil removed from the material, and this vapor is condensed partly in the conduit 42 and in the final discharge stack 47. This oil vapor forms a liquid coating on the walls of the conduit and stack and gradually accumulates and flows downwardly. Some of this condensed oil may be collected in a hopper or trough 50 which has a discharge duct 51 which may be opened to remove any collected oil from the conduits 42 and 47. However in order to avoid any serious fire hazard, it is best to further remove the condensate from the conduit and stack and this can be done by igniting and burning the oil adhering to the conduits 42 and stack 47 in any suitable manner, for example, by applying a blow torch or other flame through the discharge duct 51. This has been found to be a safe procedure after a certain amount of oil has been condensed within the discharge duct and stack of the apparatus. This burning of the oil may be effected at suitable time intervals, for example from four to twelve hours, and the smoke from the combustion will be carried away by a chimney or stack 47. This is preferably done while the apparatus is in operation since the current of air and gas passing in the duct 42 is not combustible or explosive and thus confines the flame to the discharge end of the conduit 42 and to the chamber or discharge flue 47, so that it will not interfere with the operation of the apparatus.

It will be understood that various changes in the details, materials and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art, within the principle and scope of the invention, as expressed in the appended claims.

I claim:

1. A combined process of producing a felt-like packing material from loose fibers contaminated with oil and removing oil from the fibers which includes placing loose fibers mixed with a resinous substance between two cons earer veyor belts of open mesh material, moving the conveyors with the runs thereof at approximately the same speed above and below said fibers, and blowing through the material air heated sufficiently to volatilize oil adhering to the fibers and to cure the resinous substance to cause the fibers to adhere to each other to form a sheet of said material.

2. A process of producing a felt-like packing material from loose fibers of cotton contaminated with oil, which includes placing fibers mixed with a resin in a layer, passing the layer between two conveyor belts of open mesh material, moving the conveyors with runs thereof above and below said fibers at approximately the same speed to hold the fibers compacted, heating air to a temperature sufiicient to damage cotton if continuously exposedI there to, passing the heated air through said layer of material, and moving said layer through and out of exposure to said air at a speed sufficient to vaporize oil contained therein and set the resin and without damaging the fibers.

3. A method according to claim 2, in which said layer is exposed to the air for a period not substantially more than a minute.

4. A process according to claim 2 in which the air is heated to a temperature of not less than 325 degrees F.

5. A process of producing a felt-like material from loose fibers, which includes mixing with the fibers a resinous substance, forming the fibers into a layer, and passing through the layer air heated to a temperature sufficient to set the resinous substance and to cause the same to adhere to the fibers, said fibers including cotton fibers contaminated with oil, and vaporizing oil from said fibers by the heating and carrying off the oil vapors in the air passing through said layer.

6. A process of producing a felt-like materal in sheet form from cotton fibers contaminated with oil, which comprises mixing with the contaminated fibers a resinous substance, forming the fibers into a layer, and subjecting the layer to heated air for volatilizing the oil contaminating the fibers and for bonding the fibers to each other with said resinous substance during the removal of oil from said layer.

7. A process according to claim 6 in which the resinous substance is a phenolic resin and in which the temper;- ture of the air is approximately 350 degrees F.

8. A process according to claim 6 in which the resinous substance is a vinyl resin and in which the temperature of the air is approximately 430 degrees F.

9. A process of removing a relatively heavy oil which will vaporize only at elevated temperatures from loose separated fibers contaminated therewith and simultaneously melting dry finely divided plastic materials interspersed with the fibers which comprises the steps of:

(a) arranging the loose separated fibers in a layer of substantially uniform thickness, said fibers being interspersed with dry finely divided plastic materials;

(b) passing said layer through an oil volatilizing zone and between and through two conveyors pervious to the flow of air, one of which is below and supports said loose separated fibers and the other of which is above said separated fibers and holds said separated fibers on the conveyor below and against the flow of heated air which would normally blow the fibers off the conveyor;

(c) heating the air to a temperature above that at which the heavy oil will volatilize, said temperature being above the temperature which will char the fibers if exposed to the heated air for any appreciable length of time and above the temperature re quired to melt said plastic materials;

(d) passing said air through the conveyors and the separated fibers at a velocity sufiicient to carry off the volatilized oil with the heated air stream; and

(e) moving said conveyors through said volatilizing zone and at a speed relative to the temperature of 5 the heated air which when considered with the latent heat of fusion or the plastic materials will result in uncharred fibers coated with and bound together with plastic when dried such that the fibers will not char.

10. A process in accordance with claim 9 in which the air is heated above 325 degrees F.

11. A process in accordance with claim 9 in which the speed of advance of the layer through the heating zone is not less than seven lineal feet per minute but in no event is the length of the heating zone such that the layer traverses the heating zone in more than a minute.

12. A process in accordance with claim 9 in which the air is heated above 325 degrees F. and the speed of advance of the layer through the heating zone is not less than seven lineal feet per minute but in no event is the length of the heating zone such that the layer traverses the heating zone in more than a minute.

13. A process of removing mineral oil from fibers in cluding cotton fibers contaminated therewith, which includes the step of arranging the fibers in a layer of substantially uniform thickness, passing the layer successively through currents of air heated to a temperature above that to which cotton fibers may be exposed without clan..- age for periods of time exceeding one minute and passing said air through said layer srccessively in opposite directions, and adding fresh heated air to the vapor containing air which has passed through the layer to reduce the combustible vapor content of the resulting mixture before passing the same again through said layer, to render said mixture non-combustible.

14. A process of removing a relatively heavy oil which will vaporize only at elevated temperatures from loose separated fibers contaminated therewith which comprises the steps of:

(a) arranging the loose separated fibers in a layer of substantially uniform thickness;

(b) passing said layer through an oil volatilizing zone and between and through two conveyors pervious to the flow of air, one of which is below and supports said loose separated fibers and the other of which is above said separated fibers and holds said separated fibers on the conveyor below and against the flow of heated air which would normally blow the fibers oil the conveyor;

(0) heating the air to a temperature above that at which the heavy oil will volatilize, said temperature being above the temperature which will char the fibers if exposed to the heated air for any appreciable length of time;

(d) passing said air through the conveyors and the separated fibers at a velocity sufiicient to carry ofi the volatilized oil with the heated air stream; and

(6) moving said conveyors through said volatilizing zone and at a speed relative to the temperature of the heated air such that the fibers will not char.

15. A process according to claim 14 in which the heated air is passed alternately in opposite directions through said layer.

16. A process according to claim 14- including the step or" adding fresh heated air to the air which has passed through said layer in one direction to reduce the percentage of oil vapors in the air before passing again through said layer, to reduce the vapor content of the air to a degree at which the mixture of air and vapor is noncombustible. V

17. A process according to claim 14- including the steps of condensing in a stack oil from the vapor contained in said air after it is passed through said layer, and removing the condensed oil from the stack.

18. A process in accordance with claim 14 in which the air is heated above 325 degrees F.

19. A process in accordance with claim 14 in which the speed of advance of the layer through the heating zone is not less than seven lineal feet per minute but in 3 2" no event is the length of the heating zone such that the layer traverses the heating zone in more than a minute. 20. A process in accordance with claim 14 in which the air is heated above 325 degrees F. and the speed of ad- 5 Vance of the layer through the heating zone is not less than seven lineal feet per minute but in no event is the length of the heating zone such that the layer traverses the heating zone in more than a minute.

References Cited in the file of this patent UNITED STATES PATENTS Woodrufi Aug. 20, 1935 Courtright Mar. 14, 1 50 Wood et a1. Mar. 28, 1950 Meauze et al Dec. 28, 1954 Palmer Nov. 8, 1960 FOREIGN PATENTS Great Britain J an. 27, 1954 

1. A COMBINED PROCESS OF PRODUCING A FELT-LIKE PACKING MATERIAL FROM LOOSE FIBERS CONTAIMINATED WITH OIL AND REMOVING OIL FROM THE FIBERS, WHICH INCLUDES PLACING LOOSE FIBERS MIXED WITH A RESINOUS SUBSTGANCE BETWEEN TWO CONVEYOR BELTS OF OPEN MESH MATERIAL, MOVING THE CONVEYORS WITH THE RUNS THEREOF AT APPROXIMATELY THE SAME SPEED ABOVE AND BELOW SAID FIBERS, AND BLOWING THROUGH THE MATERIAL AIR HEATED SUFFICIENTLY TO VOLATILIZE OIL ADHERING TO THE FIBERS AND TO CURE THE RESINOUS SUBSTANCE TO CAUSE THE FIBERS TO ADHERE TO EACH OTHER TO FORM A SHEET OF SAID MATERIAL. 